I like the overall composition, but there are two things that are obviously out of whack. One is the 'halo' around the rocks - a sure sign that these areas were over-Photoshopped. The other, more obvious problem with the rock stacks is that they are light-colored on the inside with a dark edge all around. I imagine you probably were trying to lighten the stacks and get more detail, but didn't want to get too close to the edges.

The good news is that its a great picture and those problems are easily fixable...